I need help with my math problem please!

Question

Find the indicated term in the expansion of the given binomial.

The term containing b¹⁰

 in the expansion of (a + b²)¹⁸

Answer 1

term with b^10 in (a+b^2)^18

18C5(a^13)(b^2)^5

18!/5!13!(a^13)(b^10)

= 18x17x16x15x14/5x4x3x2)(a^13)(b^10)

=3x17x4x3x14)(a^13)(b^10)

= 8966a^13b^10